COLUMBUS, Ohio (AP) -
Top-ranked Ohio State's national title hopes teetered on a timeout, the ball inches from a first down for Illinois.

Illini coach Ron Zook changed his mind, decided to go for it on fourth down and that was the beginning of the end for the Buckeyes' hopes of redeeming themselves in this season's national championship game.

Juice Williams provided the big plays on the ground and through the air, spurring the Illini to a stunning 28-21 victory on Saturday night and throwing open the national title race for a bunch of teams that needed the Buckeyes to lose.

"I know 'shock the world' is overused," Illini linebacker J Leman said. "It is pretty shocking to most people, but not to the guys in the locker room."

Marcus Thomas' interception gave Illinois the ball with 8:09 left at its own 24. And Ohio State would never get it back.

The Illini lined up to punt on a fourth-and-inches at their own 34 with 6:53 left while grasping a 28-21 lead, but Buckeyes coach Jim Tressel called timeout and Zook reconsidered after being prodded by his quarterback.

Illinois defensive back Brian Gamble makes a touchdown reception in the end zone during the second quarter. (AP Photo/Jay LaPrete)

"I said, 'Coach, you don't think we can get a half an inch?"' Williams said amid the uproar of the postgame celebration. "He looked at me and got on the headset to (offensive coordinator Mike) Locksley. He (Zook) said, 'If you don't get it, I'll hurt you."

Williams sneaked for the first down and twice more he converted third-and-long on quarterback draws to burn the clock.

Tressel said of the timeout, "I'd like to have that one back."

It was the first time Illinois (8-3, 5-2 Big Ten) had beaten a No. 1 since 1956, and the first time it had done it away from home. The defeat also ended a conference and school streak of 20 Big Ten wins in a row by Ohio State (10-1, 6-1).

"It's (my) last time in the Horseshoe and it's the last game I'll remember for the rest of my life," Ohio State offensive tackle Kirk Barton said.

Williams, criticized at times because of his errant passing, tossed four touchdown passes. He finished 12-of-22 passing for 140 yards and carried 16 times for 70 yards.

The Buckeyes, who were in first-place in the BCS standings and two victories away from a second consecutive trip to the national title game, became the second No. 1 to lose this season. Only Kansas and Hawaii remained unbeaten in major college football, but both played later Saturday night.

All those who doubted the Buckeyes because of what they called a weak schedule must feel vindicated.

Who will be No. 1 now? Maybe, LSU - again. The Tigers lost as the top-ranked team to Kentucky earlier in the season. Count Oregon, Oklahoma, Missouri and even West Virginia among the others happy to see the Buckeyes get beat. All now have a better chance at reaching the national title game, thanks to the Illini.

The Illini rushed for 260 yards against an Ohio State defense that came in allowing just 65 yards on the ground per game. Rashard Mendenhall set an Illinois season record (1,402 yards) while rushing for 88 yards on 26 carries.

The defeat not only crippled Ohio State's dreams of a national championship, it knocked the Buckeyes into a tie for the top spot in the Big Ten because of Michigan's earlier loss to Wisconsin.

Not since Nov. 14, 1959, had Michigan and Ohio State both lost the week before their annual year-end grudge match, which once again will decide the Big Ten.

Ohio State's Todd Boeckman had his worst game in his first year as a starter. He completed 13 of 23 passes for 156 yards with three interceptions. Thomas had one pick and forced another in the Illinois end zone in the third quarter by tipping it to teammate Antonio Steele.

The Illini opened a 28-14 lead with a drive built on the running of Mendenhall and Williams. Mendenhall had 17 yards in the march, with Williams going for 16 and also hitting Brian Gamble on a 15-yard gainer. Williams, who has been replaced late in games, finished it off with a 31-yard scoring pass to a wide-open Marcus Wilkins at the goal line.

The Buckeyes came right back to cut the lead to 28-21 with a 76-yard drive of their own, with Boeckman - never known as a runner - picking up 35 yards on the first snap. The Buckeyes scored on Chris Wells' 18-yard run to the right corner of the end zone.

After forcing an Illini punt, the Buckeyes were moving the ball again when Boeckman's deep pass into double coverage was intercepted by Thomas, who leaped high to reach the ball ahead of Brian Robiskie.

"I knew right away I underthrew the ball," said Boeckman, harassed all day and sacked twice.

Wells ran for 76 yards on 20 carries and scored on runs of 11 and 17 yards.

The Buckeyes had won their last 28 regular-season games and hadn't lost at all since getting routed 41-14 by Florida in the BCS title game. Zook played a big part in building those Gators, before he was fired by Florida in 2004.

The Zooker got the Buckeyes again.

A year ago the Illini were 2-10, but they showed signs of improvement for the first time in years in a 17-10 loss to No. 1 Ohio State. The year before the Buckeyes beat Illinois 40-2.

"We said two years ago when we were here," Zook said, "it would be a different story when we came back."